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    // console.log(c1.getContext)
    const cvsCtx = c1.getContext('2d')
    // console.log(cvsCtx);
    // 画圆(圆心x，圆心y，半径,开始角度，结束角度，逆时针还是顺时针) 默认顺时针flase
    cvsCtx.arc(300,200,50,0,Math.PI / 2 , true)
    // 填充
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    //路径 划线
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